Exercise device



FIG. 1 is a front elevational view of an exercise device, showing my new design, the rear elevational view being a mirror image thereof;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof; and,

FIG. 4 is a side elevational view from the left side of FIG. 1; and the side elevational view from the right side of FIG. 1 being a mirror image thereof. 

The ornamental design for an exercise device, as shown and described. 